The invention relates to a power transformer for a switching power supply, particularly for stud welding devices according to the preamble of claim 1, and a switching power supply comprising a power transformer.
Known power transformers of this kind for switching power supplies as used for example in stud welding engineering have to be capable of giving off a power output of several kW, e.g. up to 50 kW. Owing to this high output, known power transformers are heavy and have large dimensions. As the power transformers usually determine the dimensions as well as the weight of switching power supplies for the most part, such switching power supplies have the disadvantage that they are unwieldy because of the largeness of their structure and because of their weight. Furthermore, as a result of their large size, such power transformers have a relatively high power dissipation in the core (hysteretic losses) and in the windings (ohmic losses) when operating and are expensive to manufacture because of their size required.
Moreover, all the peripheral components of a switching power supply having a known power transformer have to be designed for very high outputs because of the relatively high losses of the power transformer. For this reason, the construction of such a switching power supply is expensive and complex.
The object of the present invention is to provide a power transformer which has lower losses when operating, which is constructed to be lighter and smaller and which can be manufactured in an easy and cost-efficient way, and a switching power supply comprising such a power transformer.
According to the invention, the object is achieved with the features of claims 1 and 10.
Further advantageous embodiments of the invention are apparent from the subclaims.